1. Technical Field
The present disclosure generally relates to information handling systems (IHS) and in particular to multi-phase voltage regulation within information handling systems.
2. Description of the Related Art
As the value and use of information continue to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system (IHS) generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems typically utilize multi-phase voltage regulators (VR) to supply power to loads such as central processing units (CPUs) and memory. These multi-phase VRs are expected to deliver power from a primary source to an electrical load at a specified current, voltage, and power efficiency.
As processor speeds and microprocessor integration into information handling systems continue to increase, power regulation system demands also increase. Multi-phase voltage regulators include a number of discrete components including inductors and capacitors. In addition, the multi-phase VR typically utilizes a pulse width modulation (PWM) controller to control the individual phases of the multi-phase VR. The current accuracy of a power converter depends on the PWM controller's internal sense gain, and sense devices such as a current-shunt inductor or a direct current resistance (DCR) of an inductor. Inaccurate current information can adversely impact the multi-phase VR and the overall system performance. With typical component tolerances being relatively large compared with a specified accuracy requirement for particular microelectronic devices, higher accuracy components can be utilized. However, the use of higher accuracy components are directly related to increased system implementation costs while providing relatively low yield. For example, the cost difference can be in the range of 20-50 times for utilizing a resistor having a tolerance of 0.1% instead of a 1% tolerance. During a calibration process, component tolerances and power device mismatches result in unequal sharing of the load current among the phases of a multi-phase regulator. This unequal sharing of load current causes inadequate operation of, and excessive heat generation in, the power devices corresponding to the active phases of a multi-phase power supply.
Servers are requiring ever increasing accuracy for power telemetry data to be used in system level power and thermal management algorithms. For example, CPU power management algorithms poll CPU load current information from CPU core voltage (Vcore) Voltage Regulators (VRs) in order to optimize CPU performance versus power consumption while still maintaining safe system operation. Current sense accuracy directly impacts system performance, power saving and reliability. Consequently, tighter current sense accuracy targets are specified for many next generation servers. As a result of these design challenges, the power requirements for emerging leading edge technology microprocessors have become very difficult to satisfy.